a human, using stereoscopic cameras. ♪ and even stop itself if it has to. ♪thetechnologymaybe hard to imagine. but why you would want it... is not. the 2014 e-class. it doesn't just see the future. it is the future. >>> continuing coverage now of the boston bombings. we spoke with a bay area bomb expert for son insight on how investigators approach the aftermath of a bomb scene. putting the puzzle together requires caution, dedication and compassion for the victim. >> atf explosives enforcement officer j.d. powell has worked more high profile cases including the oklahoma bombing which took place 18 years ago today. >> i've been doing bomb disposal work now for 37 years. and no one is ever prepared for a scene like that. >> reporter: he could not talk specifically about boston given the ongoing investigation. but he's dealt with numerous situations where a suspect may have set boobie traps. >> you don't go hard charging through the door. you have plans, you take precautions. you try to get as much intelligence as you probably can at the scene. you may feel if the place is booby trap